Rabbi Hamadani was the chief Rabbi of the Iranian community since 1994.

In August 2000, he met with Iranian President Mohammad Khatami for the first time.[2] In 2003, Cohen and Member of Parliament Morris Motamed met with Khatami at Yusef Abad Synagogue which was the first time a President of Iran had visited a synagogue since the Islamic Revolution. For the event, Cohen led the opening the Torah scroll ark and the reciting of prayers.